From a79328b02bab1fa700093ea7a6a89a25b76abebf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Vants?= <andrevants@icloud.com>
Date: Mon, 9 May 2022 20:13:35 -0300
Subject: [PATCH 1/5] Removed optional from event chainId

---
 Sources/WalletConnect/Engine/SessionEngine.swift      | 2 +-
 Sources/WalletConnect/Types/Session/SessionType.swift | 2 +-
 Sources/WalletConnect/WalletConnectClient.swift       | 2 +-
 Tests/IntegrationTests/ClientTest.swift               | 6 +++---
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Sources/WalletConnect/Engine/SessionEngine.swift b/Sources/WalletConnect/Engine/SessionEngine.swift
index 70d09e162..dad8da9f4 100644
--- a/Sources/WalletConnect/Engine/SessionEngine.swift
+++ b/Sources/WalletConnect/Engine/SessionEngine.swift
@@ -107,7 +107,7 @@ final class SessionEngine {
         }
     }
     
-    func emit(topic: String, event: SessionType.EventParams.Event, chainId: Blockchain?, completion: ((Error?)->())?) {
+    func emit(topic: String, event: SessionType.EventParams.Event, chainId: Blockchain, completion: ((Error?)->())?) {
         guard let session = sessionStore.getSession(forTopic: topic), session.acknowledged else {
             logger.debug("Could not find session for topic \(topic)")
             return
diff --git a/Sources/WalletConnect/Types/Session/SessionType.swift b/Sources/WalletConnect/Types/Session/SessionType.swift
index a83738e81..6e025be83 100644
--- a/Sources/WalletConnect/Types/Session/SessionType.swift
+++ b/Sources/WalletConnect/Types/Session/SessionType.swift
@@ -70,7 +70,7 @@ internal enum SessionType {
     
     struct EventParams: Codable, Equatable {
         let event: Event
-        let chainId: Blockchain?
+        let chainId: Blockchain
 
         struct Event: Codable, Equatable {
             let name: String
diff --git a/Sources/WalletConnect/WalletConnectClient.swift b/Sources/WalletConnect/WalletConnectClient.swift
index aaa6c5549..a6ccddeff 100644
--- a/Sources/WalletConnect/WalletConnectClient.swift
+++ b/Sources/WalletConnect/WalletConnectClient.swift
@@ -259,7 +259,7 @@ public final class WalletConnectClient {
     ///   - topic: Session topic
     ///   - params: Event Parameters
     ///   - completion: calls a handler upon completion
-    public func emit(topic: String, event: Session.Event, chainId: Blockchain?, completion: ((Error?)->())?) {
+    public func emit(topic: String, event: Session.Event, chainId: Blockchain, completion: ((Error?)->())?) {
         sessionEngine.emit(topic: topic, event: event.internalRepresentation(), chainId: chainId, completion: completion)
     }
     
diff --git a/Tests/IntegrationTests/ClientTest.swift b/Tests/IntegrationTests/ClientTest.swift
index bbe156283..debcfc238 100644
--- a/Tests/IntegrationTests/ClientTest.swift
+++ b/Tests/IntegrationTests/ClientTest.swift
@@ -292,7 +292,7 @@ final class ClientTests: XCTestCase {
     
     func testSessionEventSucceeds() async {
         let proposerReceivesEventExpectation = expectation(description: "Proposer receives event")
-        let namespace = Namespace(chains: [], methods: [], events: ["type1"])
+        let namespace = Namespace(chains: [], methods: [], events: ["type1"]) // TODO: Fix namespace with empty chain array / protocol change
         let uri = try! await proposer.client.connect(namespaces: [namespace])!
 
         try! responder.client.pair(uri: uri)
@@ -301,7 +301,7 @@ final class ClientTests: XCTestCase {
             self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [namespace])
         }
         responder.onSessionSettled = { [unowned self] session in
-            responder.client.emit(topic: session.topic, event: event, chainId: nil, completion: nil)
+            responder.client.emit(topic: session.topic, event: event, chainId: Blockchain("eip155:1")!, completion: nil)
         }
         proposer.onEventReceived = { event, _ in
             XCTAssertEqual(event, event)
@@ -321,7 +321,7 @@ final class ClientTests: XCTestCase {
             self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         proposer.onSessionSettled = { [unowned self] session in
-            proposer.client.emit(topic: session.topic, event: event, chainId: nil) { error in
+            proposer.client.emit(topic: session.topic, event: event, chainId: Blockchain("eip155:1")!) { error in
                 XCTAssertNotNil(error)
             }
         }

From 6a39525131895d1d3a38ec96531c34c84d36cb96 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Vants?= <andrevants@icloud.com>
Date: Mon, 9 May 2022 20:39:02 -0300
Subject: [PATCH 2/5] Removed optional from request chainId

---
 .../WalletConnect/Engine/SessionEngine.swift  |  22 +--
 .../NetworkInteractor/NetworkInteractor.swift |   2 +-
 Sources/WalletConnect/Request.swift           |   6 +-
 .../Types/Session/SessionType.swift           |   2 +-
 .../Types/Session/WCSession.swift             |   1 +
 .../SessionEngineTests.swift                  | 151 +++++++++---------
 Tests/WalletConnectTests/Stub/Stubs.swift     |   2 +-
 7 files changed, 91 insertions(+), 95 deletions(-)

diff --git a/Sources/WalletConnect/Engine/SessionEngine.swift b/Sources/WalletConnect/Engine/SessionEngine.swift
index dad8da9f4..191e11c8d 100644
--- a/Sources/WalletConnect/Engine/SessionEngine.swift
+++ b/Sources/WalletConnect/Engine/SessionEngine.swift
@@ -218,20 +218,14 @@ final class SessionEngine {
             networkingInteractor.respondError(for: payload, reason: .noContextWithTopic(context: .session, topic: topic))
             return
         }
-        if let chain = request.chainId {
-            guard session.hasNamespace(for: chain) else {
-                networkingInteractor.respondError(for: payload, reason: .unauthorizedTargetChain(chain.absoluteString))
-                return
-            }
-            guard session.hasNamespace(for: chain, method: request.method) else {
-                networkingInteractor.respondError(for: payload, reason: .unauthorizedMethod(request.method))
-                return
-            }
-        } else {
-            guard session.hasNamespace(for: nil, method: request.method) else {
-                networkingInteractor.respondError(for: payload, reason: .unauthorizedMethod(request.method))
-                return
-            }
+        let chain = request.chainId
+        guard session.hasNamespace(for: chain) else {
+            networkingInteractor.respondError(for: payload, reason: .unauthorizedTargetChain(chain.absoluteString))
+            return
+        }
+        guard session.hasNamespace(for: chain, method: request.method) else {
+            networkingInteractor.respondError(for: payload, reason: .unauthorizedMethod(request.method))
+            return
         }
         onSessionRequest?(request)
     }
diff --git a/Sources/WalletConnect/NetworkInteractor/NetworkInteractor.swift b/Sources/WalletConnect/NetworkInteractor/NetworkInteractor.swift
index 46f65ae26..143dc9279 100644
--- a/Sources/WalletConnect/NetworkInteractor/NetworkInteractor.swift
+++ b/Sources/WalletConnect/NetworkInteractor/NetworkInteractor.swift
@@ -264,6 +264,6 @@ class NetworkInteractor: NetworkInteracting {
     
     func getChainId(_ request: WCRequest) -> String? {
         guard case let .sessionRequest(payload) = request.params else {return nil}
-        return payload.chainId?.absoluteString
+        return payload.chainId.absoluteString
     }
 }
diff --git a/Sources/WalletConnect/Request.swift b/Sources/WalletConnect/Request.swift
index 36d83d5f9..b9e7b07f0 100644
--- a/Sources/WalletConnect/Request.swift
+++ b/Sources/WalletConnect/Request.swift
@@ -6,9 +6,9 @@ public struct Request: Codable, Equatable {
     public let topic: String
     public let method: String
     public let params: AnyCodable
-    public let chainId: Blockchain?
+    public let chainId: Blockchain
     
-    internal init(id: Int64, topic: String, method: String, params: AnyCodable, chainId: Blockchain?) {
+    internal init(id: Int64, topic: String, method: String, params: AnyCodable, chainId: Blockchain) {
         self.id = id
         self.topic = topic
         self.method = method
@@ -16,7 +16,7 @@ public struct Request: Codable, Equatable {
         self.chainId = chainId
     }
     
-    public init(topic: String, method: String, params: AnyCodable, chainId: Blockchain?) {
+    public init(topic: String, method: String, params: AnyCodable, chainId: Blockchain) {
         self.id = Self.generateId()
         self.topic = topic
         self.method = method
diff --git a/Sources/WalletConnect/Types/Session/SessionType.swift b/Sources/WalletConnect/Types/Session/SessionType.swift
index 6e025be83..76ede5493 100644
--- a/Sources/WalletConnect/Types/Session/SessionType.swift
+++ b/Sources/WalletConnect/Types/Session/SessionType.swift
@@ -60,7 +60,7 @@ internal enum SessionType {
     
     struct RequestParams: Codable, Equatable {
         let request: Request
-        let chainId: Blockchain?
+        let chainId: Blockchain
         
         struct Request: Codable, Equatable {
             let method: String
diff --git a/Sources/WalletConnect/Types/Session/WCSession.swift b/Sources/WalletConnect/Types/Session/WCSession.swift
index b930d200d..1a620cca1 100644
--- a/Sources/WalletConnect/Types/Session/WCSession.swift
+++ b/Sources/WalletConnect/Types/Session/WCSession.swift
@@ -69,6 +69,7 @@ struct WCSession: ExpirableSequence {
         namespaces.contains{$0.chains.contains(chain)}
     }
     
+    // TODO: Remove optional for chain param, it's required now / protocol change
     func hasNamespace(for chain: Blockchain?, method: String) -> Bool {
         if let chain = chain {
             let namespacesIncludingChain = namespaces.filter{$0.chains.contains(chain)}
diff --git a/Tests/WalletConnectTests/SessionEngineTests.swift b/Tests/WalletConnectTests/SessionEngineTests.swift
index 5ca23eded..4b5b2bd93 100644
--- a/Tests/WalletConnectTests/SessionEngineTests.swift
+++ b/Tests/WalletConnectTests/SessionEngineTests.swift
@@ -124,49 +124,50 @@ final class SessionEngineTests: XCTestCase {
         XCTAssertFalse(cryptoMock.hasPrivateKey(for: session.self.publicKey!), "Responder must remove private key")
     }
     
-    func testSessionRequestEmptyNamespaceUnmatchingMethod() {
-        var didTriggerRequest = false
-        engine.onSessionRequest = { _ in didTriggerRequest = true }
-        
-        let session = WCSession.stub(isSelfController: true)
-        storageMock.setSession(session)
-        
-        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-        networkingInteractor.wcRequestPublisherSubject.send(payload)
-        
-        XCTAssertTrue(networkingInteractor.didRespondError)
-        XCTAssertFalse(didTriggerRequest)
-    }
-    
-    func testSessionRequestEmptyNamespaceMatchingMethod() {
-        var didTriggerRequest = false
-        engine.onSessionRequest = { _ in didTriggerRequest = true }
-        
-        var session = WCSession.stub(isSelfController: true)
-        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
-        storageMock.setSession(session)
-        
-        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-        networkingInteractor.wcRequestPublisherSubject.send(payload)
-        
-        XCTAssertFalse(networkingInteractor.didRespondError)
-        XCTAssertTrue(didTriggerRequest)
-    }
-    
-    func testSessionRequestUndefinedChainMatchingMethod() {
-        var didTriggerRequest = false
-        engine.onSessionRequest = { _ in didTriggerRequest = true }
-        
-        var session = WCSession.stub(isSelfController: true)
-        session.updateNamespaces([Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: [])])
-        storageMock.setSession(session)
-        
-        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-        networkingInteractor.wcRequestPublisherSubject.send(payload)
-        
-        XCTAssertTrue(networkingInteractor.didRespondError)
-        XCTAssertFalse(didTriggerRequest)
-    }
+    // TODO: Tests with nil chainId are obsolete after protocol change, check planned test before removing
+//    func testSessionRequestEmptyNamespaceUnmatchingMethod() {
+//        var didTriggerRequest = false
+//        engine.onSessionRequest = { _ in didTriggerRequest = true }
+//
+//        let session = WCSession.stub(isSelfController: true)
+//        storageMock.setSession(session)
+//
+//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
+//        networkingInteractor.wcRequestPublisherSubject.send(payload)
+//        
+//        XCTAssertTrue(networkingInteractor.didRespondError)
+//        XCTAssertFalse(didTriggerRequest)
+//    }
+//
+//    func testSessionRequestEmptyNamespaceMatchingMethod() {
+//        var didTriggerRequest = false
+//        engine.onSessionRequest = { _ in didTriggerRequest = true }
+//
+//        var session = WCSession.stub(isSelfController: true)
+//        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
+//        storageMock.setSession(session)
+//
+//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
+//        networkingInteractor.wcRequestPublisherSubject.send(payload)
+//
+//        XCTAssertFalse(networkingInteractor.didRespondError)
+//        XCTAssertTrue(didTriggerRequest)
+//    }
+//
+//    func testSessionRequestUndefinedChainMatchingMethod() {
+//        var didTriggerRequest = false
+//        engine.onSessionRequest = { _ in didTriggerRequest = true }
+//
+//        var session = WCSession.stub(isSelfController: true)
+//        session.updateNamespaces([Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: [])])
+//        storageMock.setSession(session)
+//
+//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
+//        networkingInteractor.wcRequestPublisherSubject.send(payload)
+//
+//        XCTAssertTrue(networkingInteractor.didRespondError)
+//        XCTAssertFalse(didTriggerRequest)
+//    }
     
     func testSessionRequestDefinedChainMatchingMethod() {
         var didTriggerRequest = false
@@ -198,38 +199,38 @@ final class SessionEngineTests: XCTestCase {
         XCTAssertFalse(didTriggerRequest)
     }
     
-    func testSessionRequestEmptyNamespaceDefinedChainMatchingMethod() {
-        var didTriggerRequest = false
-        engine.onSessionRequest = { _ in didTriggerRequest = true }
-        
-        var session = WCSession.stub(isSelfController: true)
-        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
-        storageMock.setSession(session)
-        
-        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: Blockchain("eip155:1")!)
-        networkingInteractor.wcRequestPublisherSubject.send(payload)
-        
-        XCTAssertTrue(networkingInteractor.didRespondError)
-        XCTAssertFalse(didTriggerRequest)
-    }
-    
-    func testSessionRequestMultiNamespaceUndefinedChainMatchingMethod() {
-        var didTriggerRequest = false
-        engine.onSessionRequest = { _ in didTriggerRequest = true }
-        
-        var session = WCSession.stub(isSelfController: true)
-        session.updateNamespaces([
-            Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: []),
-            Namespace(chains: [], methods: ["someMethod"], events: [])
-        ])
-        storageMock.setSession(session)
-        
-        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-        networkingInteractor.wcRequestPublisherSubject.send(payload)
-        
-        XCTAssertFalse(networkingInteractor.didRespondError)
-        XCTAssertTrue(didTriggerRequest)
-    }
+//    func testSessionRequestEmptyNamespaceDefinedChainMatchingMethod() {
+//        var didTriggerRequest = false
+//        engine.onSessionRequest = { _ in didTriggerRequest = true }
+//
+//        var session = WCSession.stub(isSelfController: true)
+//        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
+//        storageMock.setSession(session)
+//
+//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: Blockchain("eip155:1")!)
+//        networkingInteractor.wcRequestPublisherSubject.send(payload)
+//
+//        XCTAssertTrue(networkingInteractor.didRespondError)
+//        XCTAssertFalse(didTriggerRequest)
+//    }
+//
+//    func testSessionRequestMultiNamespaceUndefinedChainMatchingMethod() {
+//        var didTriggerRequest = false
+//        engine.onSessionRequest = { _ in didTriggerRequest = true }
+//
+//        var session = WCSession.stub(isSelfController: true)
+//        session.updateNamespaces([
+//            Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: []),
+//            Namespace(chains: [], methods: ["someMethod"], events: [])
+//        ])
+//        storageMock.setSession(session)
+//
+//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
+//        networkingInteractor.wcRequestPublisherSubject.send(payload)
+//
+//        XCTAssertFalse(networkingInteractor.didRespondError)
+//        XCTAssertTrue(didTriggerRequest)
+//    }
     
     func testSessionRequestMultiNamespaceDefinedChainMatchingMethod() {
         var didTriggerRequest = false
diff --git a/Tests/WalletConnectTests/Stub/Stubs.swift b/Tests/WalletConnectTests/Stub/Stubs.swift
index f3eedd741..6a6970480 100644
--- a/Tests/WalletConnectTests/Stub/Stubs.swift
+++ b/Tests/WalletConnectTests/Stub/Stubs.swift
@@ -71,7 +71,7 @@ extension WCRequestSubscriptionPayload {
         return WCRequestSubscriptionPayload(topic: topic, wcRequest: method.asRequest())
     }
     
-    static func stubRequest(topic: String, method: String, chainId: Blockchain?) -> WCRequestSubscriptionPayload {
+    static func stubRequest(topic: String, method: String, chainId: Blockchain) -> WCRequestSubscriptionPayload {
         let params = SessionType.RequestParams(
             request: SessionType.RequestParams.Request(method: method, params: AnyCodable(EmptyCodable())),
             chainId: chainId)

From a57f0464e3b6c21b406c3e1d430ab071868f8a37 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Vants?= <andrevants@icloud.com>
Date: Mon, 9 May 2022 21:02:36 -0300
Subject: [PATCH 3/5] Fixed integration test case

---
 Tests/IntegrationTests/ClientTest.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Tests/IntegrationTests/ClientTest.swift b/Tests/IntegrationTests/ClientTest.swift
index debcfc238..2d2296360 100644
--- a/Tests/IntegrationTests/ClientTest.swift
+++ b/Tests/IntegrationTests/ClientTest.swift
@@ -292,7 +292,7 @@ final class ClientTests: XCTestCase {
     
     func testSessionEventSucceeds() async {
         let proposerReceivesEventExpectation = expectation(description: "Proposer receives event")
-        let namespace = Namespace(chains: [], methods: [], events: ["type1"]) // TODO: Fix namespace with empty chain array / protocol change
+        let namespace = Namespace(chains: [Blockchain("eip155:1")!], methods: [], events: ["type1"]) // TODO: Fix namespace with empty chain array / protocol change
         let uri = try! await proposer.client.connect(namespaces: [namespace])!
 
         try! responder.client.pair(uri: uri)

From d79213843f851683db06436298a091fca9b3a019 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Vants?= <andrevants@icloud.com>
Date: Wed, 11 May 2022 00:51:03 -0300
Subject: [PATCH 4/5] Added validation checks for empty namespaces

---
 .../WalletConnect/Engine/PairingEngine.swift  |  6 ++
 .../WalletConnect/Engine/SessionEngine.swift  |  3 +-
 .../SessionStateMachineValidating.swift       | 13 +--
 Sources/WalletConnect/Namespace.swift         | 21 +++++
 .../WalletConnect/WalletConnectClient.swift   |  5 +-
 .../WalletConnect/WalletConnectError.swift    |  3 +
 Tests/IntegrationTests/ClientTest.swift       | 22 ++---
 .../SessionEngineTests.swift                  | 80 +------------------
 8 files changed, 48 insertions(+), 105 deletions(-)

diff --git a/Sources/WalletConnect/Engine/PairingEngine.swift b/Sources/WalletConnect/Engine/PairingEngine.swift
index af5bbedf9..5aea81af3 100644
--- a/Sources/WalletConnect/Engine/PairingEngine.swift
+++ b/Sources/WalletConnect/Engine/PairingEngine.swift
@@ -70,6 +70,12 @@ final class PairingEngine {
     }
     func propose(pairingTopic: String, namespaces: Set<Namespace>, relay: RelayProtocolOptions, completion: @escaping ((Error?) -> ())) {
         logger.debug("Propose Session on topic: \(pairingTopic)")
+        do {
+            try Namespace.validate(namespaces)
+        } catch {
+            completion(error)
+            return
+        }
         let publicKey = try! kms.createX25519KeyPair()
         let proposer = Participant(
             publicKey: publicKey.hexRepresentation,
diff --git a/Sources/WalletConnect/Engine/SessionEngine.swift b/Sources/WalletConnect/Engine/SessionEngine.swift
index 191e11c8d..75e625035 100644
--- a/Sources/WalletConnect/Engine/SessionEngine.swift
+++ b/Sources/WalletConnect/Engine/SessionEngine.swift
@@ -145,7 +145,8 @@ final class SessionEngine {
         }.store(in: &publishers)
     }
 
-    func settle(topic: String, proposal: SessionProposal, accounts: Set<Account>, namespaces: Set<Namespace>) {
+    func settle(topic: String, proposal: SessionProposal, accounts: Set<Account>, namespaces: Set<Namespace>) throws {
+        try Namespace.validate(namespaces)
         let agreementKeys = try! kms.getAgreementSecret(for: topic)!
         
         let selfParticipant = Participant(publicKey: agreementKeys.publicKey.hexRepresentation, metadata: metadata)
diff --git a/Sources/WalletConnect/Engine/SessionStateMachines/SessionStateMachineValidating.swift b/Sources/WalletConnect/Engine/SessionStateMachines/SessionStateMachineValidating.swift
index 0b752f9c6..1099aab0f 100644
--- a/Sources/WalletConnect/Engine/SessionStateMachines/SessionStateMachineValidating.swift
+++ b/Sources/WalletConnect/Engine/SessionStateMachines/SessionStateMachineValidating.swift
@@ -7,17 +7,6 @@ protocol SessionStateMachineValidating {
 
 extension SessionStateMachineValidating {
     func validateNamespaces(_ namespaces: Set<Namespace>) throws {
-        for namespace in namespaces {
-            for method in namespace.methods {
-                if method.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
-                    throw WalletConnectError.invalidMethod
-                }
-            }
-            for event in namespace.events {
-                if event.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
-                    throw WalletConnectError.invalidEvent
-                }
-            }
-        }
+        try Namespace.validate(namespaces)
     }
 }
diff --git a/Sources/WalletConnect/Namespace.swift b/Sources/WalletConnect/Namespace.swift
index d6a3d22e7..4f8398fda 100644
--- a/Sources/WalletConnect/Namespace.swift
+++ b/Sources/WalletConnect/Namespace.swift
@@ -10,3 +10,24 @@ public struct Namespace: Codable, Equatable, Hashable {
         self.events = events
     }
 }
+
+internal extension Namespace {
+    
+    static func validate(_ namespaces: Set<Namespace>) throws {
+        for namespace in namespaces {
+            guard !namespace.chains.isEmpty else {
+                throw WalletConnectError.namespaceHasEmptyChains
+            }
+            for method in namespace.methods {
+                if method.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+                    throw WalletConnectError.invalidMethod
+                }
+            }
+            for event in namespace.events {
+                if event.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+                    throw WalletConnectError.invalidEvent
+                }
+            }
+        }
+    }
+}
diff --git a/Sources/WalletConnect/WalletConnectClient.swift b/Sources/WalletConnect/WalletConnectClient.swift
index a6ccddeff..f8cc9f1a5 100644
--- a/Sources/WalletConnect/WalletConnectClient.swift
+++ b/Sources/WalletConnect/WalletConnectClient.swift
@@ -170,10 +170,11 @@ public final class WalletConnectClient {
     public func approve(
         proposalId: String,
         accounts: Set<Account>,
-        namespaces: Set<Namespace>) {
+        namespaces: Set<Namespace>
+    ) throws {
             //TODO - accounts should be validated for matching namespaces
         guard let (sessionTopic, proposal) = pairingEngine.respondSessionPropose(proposerPubKey: proposalId) else {return}
-            sessionEngine.settle(topic: sessionTopic, proposal: proposal, accounts: accounts, namespaces: namespaces)
+        try sessionEngine.settle(topic: sessionTopic, proposal: proposal, accounts: accounts, namespaces: namespaces)
     }
     
     /// For the responder to reject a session proposal.
diff --git a/Sources/WalletConnect/WalletConnectError.swift b/Sources/WalletConnect/WalletConnectError.swift
index da907252b..eb9d5217d 100644
--- a/Sources/WalletConnect/WalletConnectError.swift
+++ b/Sources/WalletConnect/WalletConnectError.swift
@@ -6,6 +6,7 @@ enum WalletConnectError: Error {
     case noSessionMatchingTopic(String)
     case sessionNotAcknowledged(String)
     case pairingNotSettled(String)
+    case namespaceHasEmptyChains
     case invalidMethod
     case invalidEvent
     case invalidUpdateExpiryValue
@@ -39,6 +40,8 @@ extension WalletConnectError {
             return "Pairing is not settled on topic \(topic)."
         case .invalidUpdateExpiryValue:
             return "Update expiry time is out of expected range"
+        case .namespaceHasEmptyChains:
+            return "Namespace has an empty list of chain IDs."
         case .invalidMethod:
             return "Methods set is invalid."
         case .invalidEvent:
diff --git a/Tests/IntegrationTests/ClientTest.swift b/Tests/IntegrationTests/ClientTest.swift
index 2d2296360..6cc594f30 100644
--- a/Tests/IntegrationTests/ClientTest.swift
+++ b/Tests/IntegrationTests/ClientTest.swift
@@ -55,7 +55,7 @@ final class ClientTests: XCTestCase {
         let uri = try! await proposer.client.connect(namespaces: [Namespace.stub()])!
         try! responder.client.pair(uri: uri)
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [account], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [account], namespaces: [])
         }
         responder.onSessionSettled = { sessionSettled in
             // FIXME: Commented assertion
@@ -81,7 +81,7 @@ final class ClientTests: XCTestCase {
         try! responder.client.pair(uri: uri)
 
         responder.onSessionProposal = { [unowned self] proposal in
-            responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         responder.onSessionSettled = { sessionSettled in
             responderSettlesSessionExpectation.fulfill()
@@ -119,7 +119,7 @@ final class ClientTests: XCTestCase {
         let uri = try! await proposer.client.connect(namespaces: [Namespace.stub()])!
         _ = try! responder.client.pair(uri: uri)
         responder.onSessionProposal = {[unowned self]  proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         proposer.onSessionSettled = {[unowned self]  settledSession in
             Task {
@@ -142,7 +142,7 @@ final class ClientTests: XCTestCase {
 
         _ = try! responder.client.pair(uri: uri)
         responder.onSessionProposal = {[unowned self]  proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: proposal.namespaces)
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: proposal.namespaces)
         }
         proposer.onSessionSettled = {[unowned self]  settledSession in
             let requestParams = Request(id: 0, topic: settledSession.topic, method: method, params: AnyCodable(params), chainId: Blockchain("eip155:1")!)
@@ -180,7 +180,7 @@ final class ClientTests: XCTestCase {
         let uri = try! await proposer.client.connect(namespaces: [Namespace.stub(methods: [method])])!
         _ = try! responder.client.pair(uri: uri)
         responder.onSessionProposal = {[unowned self]  proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: proposal.namespaces)
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: proposal.namespaces)
         }
         proposer.onSessionSettled = {[unowned self]  settledSession in
             let requestParams = Request(id: 0, topic: settledSession.topic, method: method, params: AnyCodable(params), chainId: Blockchain("eip155:1")!)
@@ -211,7 +211,7 @@ final class ClientTests: XCTestCase {
 
         try! responder.client.pair(uri: uri)
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         proposer.onSessionSettled = { [unowned self] sessionSettled in
             self.proposer.client.ping(topic: sessionSettled.topic) { response in
@@ -230,7 +230,7 @@ final class ClientTests: XCTestCase {
         let uri = try! await proposer.client.connect(namespaces: [Namespace.stub()])!
         try! responder.client.pair(uri: uri)
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [account], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [account], namespaces: [])
         }
         responder.onSessionSettled = { [unowned self] sessionSettled in
             try? responder.client.updateAccounts(topic: sessionSettled.topic, accounts: updateAccounts)
@@ -253,7 +253,7 @@ final class ClientTests: XCTestCase {
         let namespacesToUpdateWith: Set<Namespace> = [Namespace(chains: [Blockchain("eip155:1")!, Blockchain("eip155:137")!], methods: ["xyz"], events: ["abc"])]
         try! responder.client.pair(uri: uri)
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         responder.onSessionSettled = { [unowned self] session in
             try? responder.client.updateNamespaces(topic: session.topic, namespaces: namespacesToUpdateWith)
@@ -275,7 +275,7 @@ final class ClientTests: XCTestCase {
         let uri = try! await proposer.client.connect(namespaces: [Namespace.stub()])!
         try! responder.client.pair(uri: uri)
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         responder.onSessionSettled = { [unowned self] session in
             Thread.sleep(forTimeInterval: 1) //sleep because new expiry must be greater than current
@@ -298,7 +298,7 @@ final class ClientTests: XCTestCase {
         try! responder.client.pair(uri: uri)
         let event = Session.Event(name: "type1", data: AnyCodable("event_data"))
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [namespace])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [namespace])
         }
         responder.onSessionSettled = { [unowned self] session in
             responder.client.emit(topic: session.topic, event: event, chainId: Blockchain("eip155:1")!, completion: nil)
@@ -318,7 +318,7 @@ final class ClientTests: XCTestCase {
         try! responder.client.pair(uri: uri)
         let event = Session.Event(name: "type2", data: AnyCodable("event_data"))
         responder.onSessionProposal = { [unowned self] proposal in
-            self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
+            try? self.responder.client.approve(proposalId: proposal.id, accounts: [], namespaces: [])
         }
         proposer.onSessionSettled = { [unowned self] session in
             proposer.client.emit(topic: session.topic, event: event, chainId: Blockchain("eip155:1")!) { error in
diff --git a/Tests/WalletConnectTests/SessionEngineTests.swift b/Tests/WalletConnectTests/SessionEngineTests.swift
index 4b5b2bd93..639fb33ce 100644
--- a/Tests/WalletConnectTests/SessionEngineTests.swift
+++ b/Tests/WalletConnectTests/SessionEngineTests.swift
@@ -59,7 +59,7 @@ final class SessionEngineTests: XCTestCase {
         
         let proposal = SessionProposal.stub(proposerPubKey: AgreementPrivateKey().publicKey.hexRepresentation)
         
-        engine.settle(topic: topicB, proposal: proposal, accounts: [], namespaces: [Namespace.stub()])
+        try? engine.settle(topic: topicB, proposal: proposal, accounts: [], namespaces: [Namespace.stub()])
         
         XCTAssertTrue(storageMock.hasSession(forTopic: topicB), "Responder must persist session on topic B")
         XCTAssert(networkingInteractor.didSubscribe(to: topicB), "Responder must subscribe for topic B")
@@ -124,51 +124,6 @@ final class SessionEngineTests: XCTestCase {
         XCTAssertFalse(cryptoMock.hasPrivateKey(for: session.self.publicKey!), "Responder must remove private key")
     }
     
-    // TODO: Tests with nil chainId are obsolete after protocol change, check planned test before removing
-//    func testSessionRequestEmptyNamespaceUnmatchingMethod() {
-//        var didTriggerRequest = false
-//        engine.onSessionRequest = { _ in didTriggerRequest = true }
-//
-//        let session = WCSession.stub(isSelfController: true)
-//        storageMock.setSession(session)
-//
-//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-//        networkingInteractor.wcRequestPublisherSubject.send(payload)
-//        
-//        XCTAssertTrue(networkingInteractor.didRespondError)
-//        XCTAssertFalse(didTriggerRequest)
-//    }
-//
-//    func testSessionRequestEmptyNamespaceMatchingMethod() {
-//        var didTriggerRequest = false
-//        engine.onSessionRequest = { _ in didTriggerRequest = true }
-//
-//        var session = WCSession.stub(isSelfController: true)
-//        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
-//        storageMock.setSession(session)
-//
-//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-//        networkingInteractor.wcRequestPublisherSubject.send(payload)
-//
-//        XCTAssertFalse(networkingInteractor.didRespondError)
-//        XCTAssertTrue(didTriggerRequest)
-//    }
-//
-//    func testSessionRequestUndefinedChainMatchingMethod() {
-//        var didTriggerRequest = false
-//        engine.onSessionRequest = { _ in didTriggerRequest = true }
-//
-//        var session = WCSession.stub(isSelfController: true)
-//        session.updateNamespaces([Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: [])])
-//        storageMock.setSession(session)
-//
-//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-//        networkingInteractor.wcRequestPublisherSubject.send(payload)
-//
-//        XCTAssertTrue(networkingInteractor.didRespondError)
-//        XCTAssertFalse(didTriggerRequest)
-//    }
-    
     func testSessionRequestDefinedChainMatchingMethod() {
         var didTriggerRequest = false
         engine.onSessionRequest = { _ in didTriggerRequest = true }
@@ -199,39 +154,6 @@ final class SessionEngineTests: XCTestCase {
         XCTAssertFalse(didTriggerRequest)
     }
     
-//    func testSessionRequestEmptyNamespaceDefinedChainMatchingMethod() {
-//        var didTriggerRequest = false
-//        engine.onSessionRequest = { _ in didTriggerRequest = true }
-//
-//        var session = WCSession.stub(isSelfController: true)
-//        session.updateNamespaces([Namespace(chains: [], methods: ["someMethod"], events: [])])
-//        storageMock.setSession(session)
-//
-//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: Blockchain("eip155:1")!)
-//        networkingInteractor.wcRequestPublisherSubject.send(payload)
-//
-//        XCTAssertTrue(networkingInteractor.didRespondError)
-//        XCTAssertFalse(didTriggerRequest)
-//    }
-//
-//    func testSessionRequestMultiNamespaceUndefinedChainMatchingMethod() {
-//        var didTriggerRequest = false
-//        engine.onSessionRequest = { _ in didTriggerRequest = true }
-//
-//        var session = WCSession.stub(isSelfController: true)
-//        session.updateNamespaces([
-//            Namespace(chains: [Blockchain("eip155:1")!], methods: ["someMethod"], events: []),
-//            Namespace(chains: [], methods: ["someMethod"], events: [])
-//        ])
-//        storageMock.setSession(session)
-//
-//        let payload = WCRequestSubscriptionPayload.stubRequest(topic: session.topic, method: "someMethod", chainId: nil)
-//        networkingInteractor.wcRequestPublisherSubject.send(payload)
-//
-//        XCTAssertFalse(networkingInteractor.didRespondError)
-//        XCTAssertTrue(didTriggerRequest)
-//    }
-    
     func testSessionRequestMultiNamespaceDefinedChainMatchingMethod() {
         var didTriggerRequest = false
         engine.onSessionRequest = { _ in didTriggerRequest = true }

From ebe89bd7bb4c1f4d8d968ef99e4c24c1823ae2ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Vants?= <andrevants@icloud.com>
Date: Wed, 11 May 2022 00:52:16 -0300
Subject: [PATCH 5/5] Fixed build

---
 Example/ExampleApp/Wallet/WalletViewController.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Example/ExampleApp/Wallet/WalletViewController.swift b/Example/ExampleApp/Wallet/WalletViewController.swift
index 08c34778c..8fc54ff81 100644
--- a/Example/ExampleApp/Wallet/WalletViewController.swift
+++ b/Example/ExampleApp/Wallet/WalletViewController.swift
@@ -158,7 +158,7 @@ extension WalletViewController: ProposalViewControllerDelegate {
         let proposal = currentProposal!
         currentProposal = nil
         let accounts = Set(proposal.namespaces.first?.chains.compactMap { Account($0.absoluteString + ":\(account)") } ?? [])
-        client.approve(proposalId: proposal.id, accounts: accounts, namespaces: proposal.namespaces)
+        try! client.approve(proposalId: proposal.id, accounts: accounts, namespaces: proposal.namespaces)
     }
     
     func didRejectSession() {